Apex domains cannot have CNAME records.
Question and response
Question
dig ngenix.net. NS
Answer
ngenix.net. 5 NS ns1.ngenix.net.
ngenix.net. 5 NS ns.ngenix.net.
Authority
The response has no authority records.
Additional
ns.ngenix.net. 5 A 93.93.93.93
ns1.ngenix.net. 5 A 93.93.92.92
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0